Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (02): 346-350.doi: 10.3866/PKU.WHXB201211302

• SOFT MATTER • Previous Articles     Next Articles

Properties and Spreading Kinetics of Water-Based Cypermethrin Microemulsions

ZHANG Long1,2, HAN Jing-Jing1, LI Jia-Jia1, LIU Tian-Qing1   

  1. 1 School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, Jiangsu Province, P. R. China;
    2 Jiangsu Animal Husbandry and Veterinary College, Taizhou 225300, Jiangsu Province, P. R. China
  • Received:2012-09-16 Revised:2012-11-26 Published:2013-01-14
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20573091) and Priority Academic Program Development of Jiangsu Higher Education Institutions, China.


Water-based cypermethrin microemulsions were prepared by adding oil to emulsified water, with ethyl butyrate as the solvent, TritonX-100 (TX-100) and sodium dodecyl benzene sulfonate (SDBS) as surfactants, and n-butyl alcohol (n-C4H9OH) as a co-surfactant. The structure and properties of the microemulsions were investigated by determining the phase diagram, and using negative-staining transmission electron microscopy, and conductivity, surface tension, dynamic light scattering, and contact angle measurements. The spreading kinetics of the microemulsions on the leaf surface of Youngfu wheat was also studied. The results showed that the cypermethrin microemulsions followed the oil-in-water model, and had a strong solubilizing effect on cypermethrin. The microemulsions showed a low contact angle, and low surface tension, and the droplet radius was about 45 nm. The kinetics for the spreading of the microemulsions on the leaf surface of Youngfu wheat fitted a second-order kinetic equation. The kinetic rate constants were 0.1090 (°)-1·min-1 (20℃) and 0.1572 (°)-1·min-1 (30℃), and the activation energy was 27.03 kJ·mol-1.

Key words: Cypermethrin, Microemulsion, Oil in water, Contact angle, Spreading kinetics